Array object in straight line but rotate object on z axis
Dupliframes Method:

The first step is to keyframe the location of desired object at the origin at the first frame (0 or 1). Then we will add a keyframe 10 frames from our first, since we want 10 iterations, at location (5,0,0) and key a rotation of 300 degrees since we would like each iteration to be rotated 30 degrees from the previous (300 = 30 degrees each iteration * 10 frames). In the curve editor we want to make sure that we're using linear interpolation (select keys and press 'T'). This makes sure that the iterations will be evenly spaced. In the Object propeties tab, find Duplication and select frames. Since we only want 10 iterations we will end at frame 10 (It may look correct if left to 100, you will have extra meshes in the same location as the last iteration. Finally when happy with the result we can convert the dulpliobjects to real objects with Ctrl-Shift-A, and Ctrl-J if desired.